The present invention is an improvement on the reciprocating dental tool disclosed in U.S. Pat. No. 4,976,625, issued Dec. 11, 1990, to the present applicant. This patent is hereby incorporated herein by reference.
In the issued U.S. Pat. No. 4,976,625, a hand-piece, including a sleeve slidingly mounted in the head of the hand-piece, is driven by a common dental rotary drill driver, and converts the rotational motion of the driver to reciprocating motion of the sleeve by means of an eccentrically rotating member. The sleeve, having an annular recess within which the eccentric rotates, is reciprocally moved together with a dental tool that is fixedly held in the sleeve or is manufactured integrally with the sleeve.
Rotation of the tool, for example, a file, around its longitudinal axis, that is, around the axis of reciprocation, is prevented by an axially oriented groove on the reciprocating sleeve. A projection from the fixed head of the hand-piece, engages the axial groove so that the tool attached to the sleeve may only translate parallel to the reciprocating axis, but may not rotate randomly around the reciprocating axis.
However, this constraint of tool motion to pure translation can limit the utility of the tool. There are times when controlled rotation of the tool may be extremely valuable and this feature is substantially lost in the U.S. Pat. No. 4,976,625 device, although undesirable random rotation of the tool is prevented.
What is needed is a tool where controlled limited oscillatory motion is combined with controlled, limited reciprocal motion when the tool works in abrading, filing or removing excess materials in the mouth, or, works on other prosthetic devices outside the mouth.